地固系GNSS/SINS组合导航正常重力间接算法

Indirect Algorithm of SINS Normal Gravity under ECEF Frame

相比导航系,GNSS/SINS组合导航在地固系计算,编排效率提高约40%,Kalman滤波效率提高约10%,即使正常重力与姿态矩阵的计算效率偏低,在地固系计算比导航系计算综合效率也提高约30%。针对地固系正常重力计算复杂的问题,提出了地固系正常重力间接算法,首先把三维直角坐标转换为大地坐标,然后在导航系计算正常重力,最后把正常重力转换到地固系,姿态矩阵也在此过程计算完毕。试验结果表明,间接法与传统方法计算精度相当,但间接法计算过程简单直观,计算效率可以提高3%~26%,尤其对于高速高精度的捷联惯导,效率提高尤为明显,具有重要的工程实用价值。

Compared with the navigation frame,processing GNSS/SINS integrated navigation in earth-centered-earthfixed(ECEF) frame is about 30%more efficient,even if the computations of nonnal gravity and attitude matrix are of low efficiency.To address the issue of computation complexity of nonnal gravity in ECEF frame,this paper proposes a new method which computes normal gravity and attitude matrix indirectly.Compared with traditional direct method,this new indirect method,which is more compact and simpler in terms of algorithm,can reach the same accuracy level.Furthermore,the computational efficiency of this new method is also higher than that of the traditional method by a factor of 3%~ 26%.The increased efficiency is particularly obvious,especially for high-speed and high-accuracy SINS.